Among the conventionally known autofocusing techniques is focal plane phase detection AF. A solid-state image sensor which achieves focal plane phase detection AF is provided with normal pixels for obtaining a pixel signal, and in addition, light-shielded pixels for pupil division of incident light, which are located at predetermined positions. More specifically, a plurality of pairs of a right-side light-shielded pixel, a right side of the light receiving surface of which is shielded from light, and a left-side light-shielded pixel, a left side of the light receiving surface of which is shielded from light, are arranged in a plurality of straight lines. The focal point position of a lens is adjusted on the basis of a phase difference obtained from the light-shielded pixels (see, for example, Patent Literature 1).